Apparatus for the electrolysis of metals



ept 4, EQZE. Hfifi94 A. CREMER APPARATUS FOR THE ELECTROLYSIS 0F METAL$Filed Oct. 1922 Patented Sept. 4, 3 3233.

ALFRED CREIiIER, 0F VERVIERS, BELGIUM.

APPARATUS FOR THE ELECTROLYSIS 0F METALS.

Application filed October 7, 1922. Serial No. 593,137.

To all whom it may concern:

Be it known that I, ALFRED CmiMnR, subject of the King of the Belgians,residing at Verviers, Belgium, have invented certain new and usefulImprovements in Apparatus for the Electrolysis of Metals, of which thefollowing is a specification.

-Electr0lytic operations for separating a metallic element from asolution in which this element is dissolved are generally carried out intanks each of which contains a certain number of electrodes suspended inthe solution. For the purpose of renewing the solution andimproving theyield, a conrtinuous circulation of the electrolyte is set up betweenthe different suocemive tanks. To this end, the solution which has donework in one tank is drawn off by a siphon which delivers it "into thenext tank.

The efiiciency of installations of this kind is limited by the densityof the current. In fact the weight of metal precipitated on the cathodesis proportional to the surface thereof and to the density of the currentused. It is therefore possible, theoretically at any rate, to considerthat the output of an electrolytic apparatus is substantiallyproportional to the density of the current per unit of surface of thecathode.

In practice the cost of the power and the quality of the metalprecipitated tend to limit this density. As regards the cost of themotive power it is known that when the density of the current increases,the expense of the motive power increases likewise.- "A certain limitfor the density of the current cannot therefore be exceeded withoutexcessive expense for motive power being in curred. Furthermore, if thedensity of the current increases, the phenomena of polarization inherentin all electrolysis also increase in intensity,the conditions favourableto a good electrolytic separation disappear and the quality of the metaldeteriorates.

The object of the present invention is to permit of the use of ordinaryhigh densities where the motive power is cheap and in particular toutilize for example hydraulic power at night, which is not otherwise reuired. It will be understood that if a 0 cap source of motive power isavailable the density of the current can be raised without excessivelyincreasing the cost of the motive power and the; benefit can also bereaped of a considerable reduction in the surface of the installationsnecessary to the same production.

To be able to use these high densities without impairing the quality ofthe metal it is necessary to modify the old electrolytic apparatus so asefiicaciously to combat the phenomena of polarization. High densitieshave already been used with rotating cathodes but this has proved to bea costly solution of the problem.

The characteristic feature of the present invention is to keep theelectrodes stationary and to impart a rapid movement to the electrolyteparallel with the surface of the electrodes, and this is obtained by combining the tanks in series so as to form a continuous channel, in whichare placed in succession groups of electrodes arranged parallel with theaxis of the channel and separated from each other by suitable volumes ofelectrolyte. It will be understood that by this arrangement a much morerapid circulation can be obtained than with the system of separatetanks, in which it is necessary to reckon also with the possible eddiescreated by the suction of the siphon in the regions near the bottom.

The invention therefore permits of the use of high densities in caseswhere motive power is cheap. In the special case of the use ofdiscontinuous forces, the channels are capable of being emptied rapidlyduring the interruption of the current for the pu of withdrawing theelectrodes from the chemical action of the bath if necessary. In spiteof the diminution of the Working hours in discontinuous working theefficiency of working is capable of exceeding the efficiency afforded bythe old methods owing to the enormous reduction of the capital sunktherein.

In the accompanying drawing, which represents diagrammatically and byway of example an installation for the electrolytic refining of copper,

Figure l is a section on the 'line AB of Figure 2; and

Figure 2 is a plan of the installation.

The installation represented comprises three long tanks or channels a,each containing three groups I; of electrodes and each corresponding tothree ordinary tanks. The channels a are supplied in parallel at one oftheir ends by means of pipes 0 leading from a distributing channel d andprovided with cocks e. At the other end of the channels a is acollecting channel 7 into which the channels a, deliver the electrolyteby pipes 9 provided with cocks h which allow the rate of flow to beregulated. Each channel is likewise provided with an overfiow pipe 11.

In the example represented the electrolyte is kept in continuouscirculation and the circuit formed by the channels d, a and f iscompleted by a collecting reservoir j, a pipe 70, in which is interposeda pump Z, and the feed reservoir m. In the collecting reservoir theelectrolyte may be subjected to filtration before it returns to thereservoir m.

In the channels a are shown groups I) each composed of two series ofelectrodes n', 32. These electrodes are placed parallel with the lengthof the channels a and consequently with the direction of theelectrolyl'te therein. The negative electrodes n and t e positiveelectrodes p alternate from one series to the other as shown in Figure2. Each group b of electrodes constitutes the elements of an ordinarytank, all the electrodes of the same group being placed in shunt withrelation to the supply conductors 1- and the return conductors s for theelectric current. These conductors are con nected together in series andare supplied for example by a source of electrical energy Each group ofelectrodes is separated irom the neighbouring groups by spaces 0 filledwith electrolyte.

The rapid circulation of the electrolyte and the alternation of theelectrodes is favorable to the homogeneity of the solution. Thisuniformity in the-composition of the solution is easily obtained, notonly because the solution returns frequently to the reservolrs where thenecessary corrections are made but also in consequence of the inter-.

ruptions of the work in the case of discontinuous working. It is alsoadvantageous, with respect to the homogeneity of the solution, to givethe channels a comparatively small depth, as in the example illustrated,wherein the de h of the channels is about one half of their width.

' It will be understood that various modifications may be made in thearrangements shown without departing from the scope of the invention.

I claim- 1. In apparatus for the electrol sis of metals, a continuouschannel, a p urality of groups of co-operatin electrodes arranged insuccession withln saidchannel, said groups being substantially isolatedfrom each other within said channel by spaces adapted to be filled withelectrolyte;

2. In apparatus for the electrolysis of metals, a continuous channel, aplurality of groups of co-operating electrodes insaid channel, saidelectrodes being arranged parallel to the longitudinal axis of saidchannel, said groups being substantially-isolated from each other withinsaid channel by spaces adapted to be filled with electrolyte.

3. In apparatus for the electrolysis of metals, a continuous channel, aplurality of groups of co-operating electrodes arranged in succession insaid channel, each group being composed of series of electrodes, theelectrodes of opposite polarity alternating from one series to the next,said groups being substantially isolated from each other within saidchannel by spaces adapted to be filled with electrolyte.

4. In apparatus for the electrolysis of metals, a continuous channel, aplurality of groups of co-operating electrodes arranged in succession insaid channel, said groups being substantially isolated from each other Mwithin said channel by spaces adapted to be filled with electrolyte, adistributing channel adapted to deliver electrolyte to one end of saidcontinuous channel, a collecting channel adapted to receive electrolytefrom the other end of said continuous channel, and means fortransferring electrolyte from said collecting channel to saiddistributing channel. 1

In ny whereof I have afiixed my signature in presence of two witnesses.

ALFRED GREMER. Witnesses H. T. E. KIRKPATRICK, H. W. PLUOKER.

